There's no tg in the title, but is there much? So far I haven't found it, although Wikipedia hints at it. It just said something about whoever touches a magic bottle releases a curse, and then has to gather female juices to fix the curse. If he doesn't then there's a bad end where the MC turns into a girl.
The game version of the story is here, and someone said the tg starts on page 671 : /s/3389ded367/63688-671
And a scene where he wakes up as a loli is also here: https://www.nicovideo.jp/watch/sm6994190 At first he doesnt realize anything is wrong as he sits on the toilet for morning pee, and wipes like a loli, but then he gradually realizes the curse has struck. His scream brings his family who don't remember him being anything other than a little sister.